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IPv4 Documentation

Operator-level documentation for teams that plan, route, and account for IPv4 address space. Written for network engineers rather than newcomers: every page assumes you know what a prefix is and gets to the practical part quickly.

Start here

Subnet calculator

Split a prefix, check host counts, and share the result as a link.

Every prefix length from /0 to /32 with masks and host counts.

Plan and track address space without spreadsheets.

By task

Planning address space. Start with address plan design, then pick a tool in the IPAM tools reference. If you run leased space alongside your own, see IPAM for leased space.

Preparing a block for production. Check reserved and bogon ranges before you announce, confirm registry records with WHOIS and RDAP, and make sure your utilization records will survive an RIR audit.

Understanding and getting an ASN. Start with ASN concepts and routing examples, then use the ASN registration walkthrough for requirements and paperwork by registry.

Moving a block between holders. Follow the transfer process stage by stage, run the block verification checklist before signing, and finish with the post-transfer checklist before the first announcement.

Sections

IPv4 addressing

Private ranges, reserved and bogon space, CGNAT.

Address planning, tooling, automation, and registry audits.

Registry & routing

ASN concepts and registration, WHOIS, and RDAP.

Process, verification, documents, escrow, and timelines by RIR.

CIDR chart, cheat sheets, and glossary.

Interactive calculators and lookups.

Looking for pricing, transfer terms, or a quote instead? Those live in IPv4 services.

Last updated on October 28, 2026